The present invention is directed to a process for the production of olefins and hydrogen from methane. In particular, the present invention provides a process for the production of ethylene, propylene and hydrogen from methane in the absence of steam or oxygen.
Olefins such as ehtylene and propylene are major chemical feedstocks. In 1981, nearly 29 billion pounds of ethylene and 14 billion pounds of propylene were produced in the United States. Ethylene is used in the production of plastics, antifreeze, fibers and solvents, while propylene finds its major uses in plastics and fibers. About 75 percent of the ethylene produced is made by the steam cracking of ethane and propane derived from natural gas (which hydrocarbons comprise less than about 12 percent of natural gas).
U.S. production of hydrogen in 1981 amounted to about 100 billion cubic feet, excluding amounts vented and used as fuel and amounts produced in petroleum refineries for captive use. Hydrogen is used as both a chemical feed and a fuel, and is generally produced by steam reforming of hydrocarbons, especially natural gas, from water gas shift reactions, from catalytic reforming of petroleum stocks and by electrolysis. It has been reported that hydrogen can be formed by the decomposition of methane over iron or nickel catalysts. This process results in the formation of coke on the catalyst, which ultimately destroys the activity of the catalyst.
U.S. Pat. No. 2,020,671 discloses the production of oxygenated organic compounds by reaction of methane or ethane and steam at temperatures of 200.degree.-700.degree. C. in the presence of catalysts selected from alkaline earth metals or any of the metals of groups IV, V, VI, VII and VIII of the periodic table, in addition to aluminum, magnesium and zinc.
U.S. Pat. No. 2,859,258 discloses the production of ethylene from methane in the presence of oxygen containing metal compounds of the second, third and fourth groups of the periodic table, such as aluminum oxide, magnesium aluminum silicate and magnesium aluminum molybdate.
U.S. Pat. Nos. 4,172,810; 4,205,194 and 4,239,658 disclose the production of hydrocarbons including ethylene, benzene, ethane, propane and the like, in the presence of a catalyst-reagent composition which comprises
(1) a group VIII noble metal having an atomic number of 45 or greater, nickel, or a group Ib noble metal having an atomic number of 47 or greater, PA1 (2) a group VIb metal oxide which is capable of being reduced to a lower oxide, and PA1 (3) a group IIa metal selected from the group consisting of magnesium and strontium composited with a passivated, spinel-coated refractory support or calcium composited with a passivated, non-zinc containing spinel-coated refractory support.
It is an object of the present invention to provide a process for the production of olefins and hydrogen from methane.
It is a further object of the present invention to provide a process for the production of olefins, particularly ethylene and propylene, as well as hydrogen from methane with low levels of coke production.